The v3 syllabus is based on the initial version of ITIL after the re-organization from the previous version where the concentration was on Service Delivery and Service SUpport. The v3 of ITIL changed that model to reflect on how ISO 20000 worked

The 2011 syllabus is based on the updated and changed version of ITIL v3. The changes were a combination of correction of omissions and addd more details._________________John Hardesty
ITSM Manager's Certificate (Red Badge)

It would be mad to do it again for such trivial differences. The foundation course is e mere overview of ITIL. An introduction to the concepts from which more detailed work can begin._________________"Method goes far to prevent trouble in business: for it makes the task easy, hinders confusion, saves abundance of time, and instructs those that have business depending, both what to do and what to hope."
William Penn 1644-1718

The way i understand is that if a person is ITIL Foundation certified(be it v1 or v2 or v3), then he/she does not need to go for ITIL 2011 foundation again.

Yes, its true that v1 and v2 has already phased out. You will find ATOs who provide v3 and the better ones provide the latest 2011 version.
What I would suggest your friend is to go through some online Foundation v2011 papers and if interested can go ahead with Intermediate level.